Grinder including enhanced sensing and component detection

ABSTRACT

A grinder including a housing, a motor within the housing, and a first handle attached to the housing and including a first sensor configured to detect the presence of a user. The grinder includes a second handle attached to a pivot arm, the pivot arm attached to the housing and configured to be pivoted around the circumference of the housing, the second handle including a second sensor configured to detect the presence of the user. The grinder includes a controller configured to control the motor based upon the detection of the presence of the user by the first sensor and second sensor, and wherein the controller prevents the motor from operating when second sensor does not detect the presence of the user.

RELATED APPLICATIONS

This applications claims the benefit of U.S. Provisional PatentApplication No. 63/282,964, filed Nov. 24, 2021, U.S. Provisional PatentApplication No. 63/370,903, filed Aug. 9, 2022, and U.S. ProvisionalPatent Application No. 63/418,136, filed Oct. 21, 2022, the entirecontent of each of which is hereby incorporated by reference.

FIELD

Embodiments described herein provide battery pack powered power tools.

SUMMARY

Embodiments described herein provide various systems and methods foroperating a device, such as a grinder. Operating machinery, such as agrinder, presents a multitude of safety hazards for both a user and theuser's surrounding environment. A grinder that includes systems andmethods for improved safety by preventing or mitigating hazardous eventsfrom occurring is advantageous for a user of the grinder.

Embodiments described herein provide a grinder that includes a guardpresence sensor for detecting the presence of a grind wheel guard on thegrinder. If the guard is determined to not be present based on theoutput of the guard presence sensor, the grinder is prevented fromoperating. If the guard is determined to be present based on the outputof the guard presence sensor, the grinder is permitted to operate. Thisprevents operation of the grinder unless the protective guard isproperly attached.

In some embodiments, a grinder requires an operator to use two hands tooperate the grinder. The presence of two hands of the operator isdetected using sensors (e.g., grip or pressure sensors, touch sensors,electromechanical sensors, etc.). For example, one sensor can be locatedin the main body handle of the grinder (e.g., above an attached batterypack) to detect the operator's first hand. A second sensor can bepositioned on the forward stabilizing second handle. The grinder mayonly be permitted to operate when the presence of both operator hands isdetected on the grinder.

In some embodiments, the grinder includes loss of control mitigation.The grinder includes a sensor configured to detect a motion (e.g.,linear, rotational, etc.) of the grinder that is indicative of a loss ofcontrol of the grinder. If a predetermined threshold of the motion isexceeded, loss of control is determined and the motor of the grinder isbraked so that the user can regain control of the stopped grinder.

In some embodiments, the grinder includes a grinder wheel that can beused to grind (e.g., cut) through a workpiece. The grinder is configuredto detect when the grinder has completed a cut through of the workpieceusing operational parameters of the grinder. Once the grinder has beendetermined to have cut through a workpiece, the motor is stopped.

In some embodiments, the grinder can detect a type of component (e.g., aparticular type of disk guard, a particular type of dust hood, etc.)connected to the grinder. The detection of the particular type ofcomponent connected to the grinder can be achieved using a sensor (e.g.,an induction coil sensor, a Hall effect sensor, an optical sensor,wireless communication, etc.) for detecting the type of the component.After the grinder determines the particular type of component connectedto the grinder, the grinder can take a control action based on thedetected type of component connected to the grinder.

In some embodiments, the grinder includes a main power tool housing thatincludes a handle for being gripped by a user. The grinder also includesan accessory device attachment portion on the main power tool housing.The accessory device attachment portion is configured to receive anaccessory device (e.g., a second handle to provide a second grip for anoperator). Having an additional grip stabilizes the grinder and improvestask efficiency and safety.

Grinders described herein include a housing, a motor within the housing,a first handle, a second handle, and a controller. The first handleincludes a first sensor configured to detect a presence of a user. Thefirst handle is attached to the housing. The second handle is attachedto a pivot arm. The pivot arm is attached to the housing and isconfigured to be pivoted around a circumference of the housing. Thesecond handle includes a second sensor configured to detect the presenceof the user. The controller is configured to control the motor basedupon the detection of the presence of the user by the first sensor andthe second sensor. The controller prevents the motor from operating whensecond sensor does not detect the presence of the user by the secondsensor.

In some aspects, the pivot arm further includes a locking mechanism. Thelocking mechanism is configured to lock the pivot arm into one of aplurality of different positions around the circumference of thehousing.

In some aspects, the plurality of different positions around thecircumference of the housing includes a left-handed position and aright-handed position.

In some aspects, the pivot arm further includes a pivot mechanismconfigured to pivot the second handle into one of a plurality ofdifferent positions with respect to the pivot arm.

In some aspects, the plurality of different positions with respect tothe pivot arm include at least two discrete positions.

In some aspects, the second handle includes a microswitch sensorconnected to a printed circuit board, the microswitch sensor configuredto detect the presence of a second hand of the user.

In some aspects, the first sensor is configured to detect a first handof the user, and the controller is configured to prevent the motor fromoperating if the first sensor does not detect the first hand of the userand the second sensor does not detect the second hand of the user.

In some aspects, the pivot arm further includes a wire routing portionthrough which wires are routed from the second handle to the housing.

In some aspects, the wire routing portion includes a first channelwithin the pivot arm and a second channel that extends into the housing.

In some aspects, the grinder further includes a wireless transmitterinside the second handle, and a wireless receiver inside the firsthandle. The wireless transmitter is configured to transmit a signal whenthe second sensor detects the presence of the user. The wirelessreceiver is configured to receive the signal and communicate to thecontroller that that the second sensor has detected the presence of theuser.

In some aspects, the second sensor is configured to detect a second handof the user, and the controller is configured to prevent the motor fromoperating if the second sensor does not detect the second hand of theuser.

Methods described herein for operating a grinder include prohibiting, bya controller, the operation of the grinder, detecting, by a firstsensor, a presence of a user's first hand, detecting, by a secondsensor, the presence of the user's second hand, and controlling, by thecontroller, a motor of the power tool based on the first sensordetecting the presence of the user's first hand and the second sensordetecting the presence of the user's second hand.

In some aspects, the method further includes determining, by thecontroller, whether the second sensor has detected the presence of theuser's second hand within a period of time after the first sensordetected the presence of the user's first hand.

In some aspects, the method further includes prohibiting, by thecontroller, the operation of the grinder if the second sensor has notdetected the presence of the user's second hand within the period oftime.

Grinders described herein include a housing, a motor located within thehousing, a first handle, a second handle, a pivot mechanism, and acontroller. The first handle includes a first sensor configured todetect the presence of a first hand of a user. The second handle isattached to a pivot arm. The pivot arm is attached to the housing and isconfigured to be pivoted around a circumference of the housing. Thesecond handle includes a second sensor configured to detect the presenceof a second hand of the user. The pivot mechanism is attached to thepivot arm and is configured to pivot the second handle into one of aplurality of different positions with respect to the pivot arm. Thecontroller is configured to control the motor based upon the detectionof the presence of the first hand of the user by the first sensor andthe second hand of the user by the second sensor. The controllerprevents the motor from operating when the second sensor does not detectthe presence of the second hand of the user.

In some aspects, the pivot arm further includes a locking mechanism. Thelocking mechanism is configured to lock the pivot arm into one of aplurality of different positions around the circumference of thehousing.

In some aspects, the plurality of different positions around thecircumference of the housing includes a left-handed position and aright-handed position.

In some aspects, the plurality of different positions with respect tothe pivot arm include at least two discrete positions.

In some aspects, the pivot arm further includes a wire routing portionthrough which wires are routed from the second handle to the housing.

In some aspects, the wire routing portion includes a first channelwithin the pivot arm and a second channel that extends into the housing.

Power tools described herein include a housing, a motor located withinthe housing, a first handle, a second handle including a sensorconfigured to detect a user characteristic, and a controller. Thecontroller is configured to control the motor based on a signal from thesensor related to the user characteristic.

In some aspects, the power tool further includes a pivot arm configuredto be pivoted into a plurality of different positions around acircumference of the housing.

In some aspects, the plurality of different positions around thecircumference of the housing include a left-handed position and aright-handed position.

In some aspects, the power tool further includes a locking mechanismconfigured to secure the pivot arm into one of the plurality ofdifferent positions around the circumference of the housing.

In some aspects, the locking mechanism includes a switch biased into alocked position.

In some aspects, the locking mechanism includes a pivot joint configuredto connect the pivot arm to the locking mechanism.

In some aspects, the pivot joint includes an aperture configured toreceive a projection of the locking mechanism to lock the pivot arm intoone of the plurality of different positions around the circumference ofthe housing.

In some aspects, the power tool further includes a pivot mechanismconfigured to pivot the second handle through a plurality of positionsrelative to the pivot arm.

In some aspects, the power tool further includes a component presencesensor configured to detect whether a component is connected to thepower tool.

In some aspects, the power tool includes a component type indicatorconfigured to provide an indication of the type of component connectedto the power tool.

In some aspects, the component is a guard and the component presencesensor is a guard presence sensor.

In some aspects, the first handle includes a first switch operable toelectrically connect a power source to the motor.

In some aspects, the power tool further includes the first switch isconfigured to function as a detector for detecting presence of a user'shand on the first handle.

In some aspects, the power tool further includes a second sensorconfigured to detect presence of a user's hand on the second handle.

In some aspects, the second sensor is one selected from the groupconsisting of: a grip sensor, a pressure sensor, a touch sensor, and anelectromechanical sensor.

In some aspects, the power tool further includes a battery packinterface. The battery pack interface is configured to receive arechargeable battery pack.

In some aspects, the power tool further includes a user input module.The user input module includes a display and an input device.

In some aspects, the display is configured to display a speed settingfor the power tool, and the input device is configured to set the speedsetting for the power tool.

In some aspects, the power tool further includes a second sensorconfigured to detect a fault condition of the power tool.

In some aspects, the second sensor is one selected from the groupconsisting of: a current sensor, a speed sensor, a Hall effect sensor, atemperature sensor, an accelerometer, a gyroscope, an inertialmeasurement unit, a pressure sensor, and an object presence sensor.

In some aspects, the controller is configured to detect at least one ofa linear motion of the power tool or a rotational motion of the powertool.

In some aspects, a loss of control of the power tool is detected basedon the at least one of the linear motion of the power tool or therotational motion of the power tool.

In some aspects, the second handle includes a printed circuit board, theprinted circuit board including one or more microswitch sensors.

In some aspects, the microswitch sensor is configured to detect the usercharacteristic.

In some aspects, the user characteristic is a presence of a user's hand.

In some aspects, the user characteristic is a grip force greater than athreshold value.

In some aspects, the second handle includes a second microswitch sensorconfigured to detect the user characteristic.

In some aspects, the power tool further includes an internal wirerouting portion configured to provide a wired electrical connectionbetween the second handle and the housing.

In some aspects, the wire routing portion includes a includes a firstchannel within the second handle, a second channel within a pivotmechanism of the second handle, and a third channel within a pivot armof the power tool.

In some aspects, the wire routing portion includes a fourth channelwithin the housing configured to route a wire to a connector forelectrically connecting the wire to the controller.

In some aspects, the second handle includes a first electrical contactand a second electrical contact configured to electrically connect toelectrical contacts on the housing.

In some aspects, the first electrical contact and the second electricalcontact are spring-loaded electrical contacts.

In some aspects, the housing includes a plurality of rails configured toslidingly receive corresponding rails of the second handle.

In some aspects, the housing includes a second plurality of railsconfigured to sliding receive the corresponding rails of the secondhandle.

In some aspects, the second plurality of rails are located on anopposite side of the housing than the plurality of rails.

In some aspects, the second handle includes a threaded screw forfastening the second handle to the housing.

In some aspects, the power tool further includes a pivoting mechanismconnected between the second handle and the housing.

In some aspects, the pivoting mechanism is configured to pivot thesecond handle through a plurality of positions relative to the housing.

In some aspects, the plurality positions includes at least two pivotingpositions relative to the housing.

In some aspects, the power tool is a grinder.

Power tools described herein include a housing, a motor located withinthe housing, a handle, a component presence sensor configured to detectwhether a component is connected to the power tool, and a controller.The controller is configured to control the motor based on a signal fromthe component presence sensor related to whether component is connectedto the power tool.

In some aspects, the power tool includes a component type indicatorconfigured to provide an indication of the type of component connectedto the power tool.

In some aspects, the component is a guard and the component presencesensor is a guard presence sensor.

In some aspects, the component presence sensor is an inductive sensor.

In some aspects, the inductive sensor includes an inductor capacitorcircuit connected to an inductance-to-digital converter.

In some aspects, the inductance-to-digital converter is configured tomeasure a proximity to metal based on changes in an alternative currentmagnetic field resulting from an interaction with a metal target.

In some aspects, the metal target is component connected to the powertool.

In some aspects, the component is a guard connected to the power tool.

In some aspects, the component presence sensor is an electromechanicalsensor that is configured to be actuated when the component is coupledto the power tool.

In some aspects, the component present sensor is an optical sensor thatis configured to detect light reflecting off of the component to detectpresence.

Power tools described herein include a housing, a motor located withinthe housing, a wireless receiver, a first handle, a second handleincluding a wireless transmitter configured to communicate with thewireless receiver, and a controller. The controller is configured tocontrol the motor based on the wireless communication between thewireless transmitter and the wireless receiver.

In some aspects, the second handle includes a battery configured topower the wireless transmitter.

In some aspects, the second handle is electrically isolated from thehousing.

Methods described herein for operating a power tool include prohibitingoperation of the power tool, detecting a first user hand on a firsthandle of the power tool, detecting a second user hand on a secondhandle of the power tool, and allowing operation of the power tool whenboth the first user hand is detected on the first handle and the seconduser hand is detected on the second user handle. Detecting the seconduser hand on the second handle of the power tool includes detecting auser characteristic using a sensor.

In some aspects, the method further includes pivoting a pivot arm into aplurality of different positions around a circumference of a housing ofthe power tool.

In some aspects, the plurality of different positions around thecircumference of the housing include a left-handed position and aright-handed position.

In some aspects, the method further includes securing, using a lockingmechanism, the pivot arm into one of the plurality of differentpositions around the circumference of the housing.

In some aspects, the method further includes the locking mechanismincludes a switch biased into a locked position.

In some aspects, the locking mechanism includes a pivot joint configuredto connect the pivot arm to the locking mechanism.

In some aspects, the method further includes receiving, at an apertureof the pivot joint, a projection of the locking mechanism to lock thepivot arm into one of the plurality of different positions around thecircumference of the housing.

In some aspects, the method further includes pivoting, using a pivotmechanism, the second handle through a plurality of positions relativeto the pivot arm.

In some aspects, the method further includes detecting, using acomponent presence sensor, whether a component is connected to the powertool.

In some aspects, the method further includes indicating, using acomponent type indicator, the type of component connected to the powertool.

In some aspects, the component is a guard and the component presencesensor is a guard presence sensor.

In some aspects, the first handle includes a first switch operable toelectrically connect a power source to the motor.

In some aspects, the method further includes detecting, using the firstswitch, presence of a user's hand on the first handle.

In some aspects, the method further includes detecting, using a secondsensor, presence of a user's hand on the second handle.

In some aspects, the second sensor is one selected from the groupconsisting of: a grip sensor, a pressure sensor, a touch sensor, and anelectromechanical sensor.

In some aspects, the method further includes receiving, at a batterypack interface, a rechargeable battery pack.

In some aspects, the power tool includes a user input module, the userinput module including a display and an input device.

In some aspects, the method further includes displaying, using thedisplay, a speed setting for the power tool, and setting, using theinput device, a speed setting for the power tool.

In some aspects, the method further includes detecting, using a secondsensor, a fault condition of the power tool.

In some aspects, the second sensor is one selected from the groupconsisting of: a current sensor, a speed sensor, a Hall effect sensor, atemperature sensor, an accelerometer, a gyroscope, an inertialmeasurement unit, a pressure sensor, and an object presence sensor.

In some aspects, the method further includes detecting, using acontroller, at least one of a linear motion of the power tool or arotational motion of the power tool.

In some aspects, the method further includes detecting a loss of controlof the power tool based on the at least one of the linear motion of thepower tool or the rotational motion of the power tool.

In some aspects, the second handle includes a printed circuit board, theprinted circuit board including a microswitch sensor.

In some aspects, the method further includes detecting, using themicroswitch sensor, the user characteristic.

In some aspects, the user characteristic is a presence of a user's hand.

In some aspects, the user characteristic is a grip force greater than athreshold value.

In some aspects, the method further includes detecting, using a secondmicroswitch sensor, the user characteristic.

In some aspects, the method further includes providing, via an internalwire routing portion, a wired electrical connection between the secondhandle and the housing.

In some aspects, the wire routing portion includes a includes a firstchannel within the second handle, a second channel within a pivotmechanism of the second handle, and a third channel within a pivot armof the power tool.

In some aspects, the wire routing portion includes a fourth channelwithin the housing, and the method further includes routing, through thefourth channel, a wire to a connector for electrically connecting thewire to a controller.

In some aspects, the method further includes electrically connecting,using a first electrical contact and a second electrical contact of thesecond handle, the second handle to electrical contacts on the housing.

In some aspects, the first electrical contact and the second electricalcontact are spring-loaded electrical contacts.

In some aspects, the method further includes slidingly receiving, at aplurality of rails of the housing, corresponding rails of the secondhandle.

In some aspects, the method further includes slidingly receiving, at asecond plurality of rails of the housing, the corresponding rails of thesecond handle.

In some aspects, the second plurality of rails are located on anopposite side of the housing than the plurality of rails.

In some aspects, the method further includes fastening, using a threadedscrew of the second handle, the second handle to the housing.

In some aspects, the power tool incudes a pivoting mechanism connectedbetween the second handle and the housing.

In some aspects, the method further includes pivoting, using thepivoting mechanism, the second handle through a plurality of positionsrelative to the housing.

In some aspects, the plurality positions includes at least two pivotingpositions relative to the housing.

In some aspects, the power tool is a grinder.

Methods described herein for detecting a presence of an accessory on apower tool include monitoring a parameter of the power tool, monitoringa motion of the power tool, detecting a change in the parameter of thepower tool, comparing, using a controller, the change in the parameterof the power tool to a predetermined threshold, determining, using thecontroller, if the change in the parameter of the power tool is lessthan the predetermined threshold, determining, when the change in theparameter of the power tool is less than the predetermined threshold,whether the motion of the power tool is greater than a motion threshold,and controlling, using the controller, a motor of the power tool whenthe motion based on whether the motion of the power tool is greater thanthe motion threshold.

In some aspects, the method further includes stopping the motor when themotion of the power tool is greater than the motion threshold.

In some aspects, the motion of the power tool is monitored using agyroscope.

In some aspects, the parameter of the power tool is a motor current.

In some aspects, the change in the parameter of the power tool is adecrease in the motor current.

Methods described herein for detecting a presence of a component on apower tool include sending a current through a coil to generate amagnetic field, inducing eddy currents in the component to generate anopposing magnetic field, detecting a change in inductance in a circuitbased on the opposing magnetic field, generating an output signalindicative of the change in inductance, determining, using a controller,whether the component is present on the power tool based on the outputsignal indicative of the change in inductance, and controlling, usingthe controller, operation of a motor based on whether the component ispresent on the power tool.

Methods described herein for operating a power tool include detecting alinear motion of the power tool, comparing the linear motion of thepower tool to a loss of control threshold, stopping operation of thepower tool when the linear motion of the power tool is greater than theloss of control threshold, detecting a rotational motion of the powertool, comparing the rotational motion of the power tool to a loss ofcontrol rotation threshold, stopping operation of the power tool whenthe rotational motion of the power tool is greater than the loss ofcontrol rotation threshold.

Methods described herein for operating a power tool include detecting alinear motion of the power tool, detecting a rotational motion of thepower tool, incrementing a linear and rotational motion accumulator wheneither the linear motion of the power tool is greater than a firstthreshold or the rotational motion of the power tool is greater than asecond threshold, comparing the linear and rotational motion accumulatorto a maximum value, and stopping operation of the power tool when thelinear and rotational motion accumulator reaches the maximum value.

Methods described herein for operating a power tool include monitoring aparameter of a motor related to a cutting operation of the power tool,and comparing the parameter of the motor to a threshold value. Thethreshold value corresponds to a completion of the cutting operation ofthe power tool. The methods further include stopping the motor when theparameter of the motor is less than the threshold value.

In some aspects, the parameter of the motor is a motor current.

Before any embodiments are explained in detail, it is to be understoodthat the embodiments are not limited in application to the details ofthe configuration and arrangement of components set forth in thefollowing description or illustrated in the accompanying drawings. Theembodiments are capable of being practiced or of being carried out invarious ways. Also, it is to be understood that the phraseology andterminology used herein are for the purpose of description and shouldnot be regarded as limiting. The use of “including,” “comprising,” or“having” and variations thereof are meant to encompass the items listedthereafter and equivalents thereof as well as additional items. Unlessspecified or limited otherwise, the terms “mounted,” “connected,”“supported,” and “coupled” and variations thereof are used broadly andencompass both direct and indirect mountings, connections, supports, andcouplings.

In addition, it should be understood that embodiments may includehardware, software, and electronic components or modules that, forpurposes of discussion, may be illustrated and described as if themajority of the components were implemented solely in hardware. However,one of ordinary skill in the art, and based on a reading of thisdetailed description, would recognize that, in at least one embodiment,the electronic-based aspects may be implemented in software (e.g.,stored on non-transitory computer-readable medium) executable by one ormore processing units, such as a microprocessor and/or applicationspecific integrated circuits (“ASICs”). As such, it should be noted thata plurality of hardware and software based devices, as well as aplurality of different structural components, may be utilized toimplement the embodiments. For example, “servers,” “computing devices,”“controllers,” “processors,” etc., described in the specification caninclude one or more processing units, one or more computer-readablemedium modules, one or more input/output interfaces, and variousconnections (e.g., a system bus) connecting the components.

Relative terminology, such as, for example, “about,” “approximately,”“substantially,” etc., used in connection with a quantity or conditionwould be understood by those of ordinary skill to be inclusive of thestated value and has the meaning dictated by the context (e.g., the termincludes at least the degree of error associated with the measurementaccuracy, tolerances [e.g., manufacturing, assembly, use, etc.]associated with the particular value, etc.). Such terminology shouldalso be considered as disclosing the range defined by the absolutevalues of the two endpoints. For example, the expression “from about 2to about 4” also discloses the range “from 2 to 4”. The relativeterminology may refer to plus or minus a percentage (e.g., 1%, 5%, 10%,or more) of an indicated value.

It should be understood that although certain drawings illustratehardware and software located within particular devices, thesedepictions are for illustrative purposes only. Functionality describedherein as being performed by one component may be performed by multiplecomponents in a distributed manner. Likewise, functionality performed bymultiple components may be consolidated and performed by a singlecomponent. In some embodiments, the illustrated components may becombined or divided into separate software, firmware and/or hardware.For example, instead of being located within and performed by a singleelectronic processor, logic and processing may be distributed amongmultiple electronic processors. Regardless of how they are combined ordivided, hardware and software components may be located on the samecomputing device or may be distributed among different computing devicesconnected by one or more networks or other suitable communication links.Similarly, a component described as performing particular functionalitymay also perform additional functionality not described herein. Forexample, a device or structure that is “configured” in a certain way isconfigured in at least that way but may also be configured in ways thatare not explicitly listed.

Other aspects of the embodiments will become apparent by considerationof the detailed description and accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a power tool according to some embodiments.

FIG. 2 illustrates a side section view of the power tool of FIG. 1according to some embodiments.

FIG. 3 illustrates a controller for the power tool of FIG. 1 accordingto some embodiments.

FIG. 4 illustrates the adjustable second handle of the power tool ofFIG. 1 according to some embodiments.

FIG. 5 illustrates the adjustable second handle of FIG. 4 according tosome embodiments.

FIG. 6 illustrates the adjustable second handle of FIG. 4 according tosome embodiments.

FIG. 7 illustrates the adjustable second handle of FIG. 4 according tosome embodiments.

FIG. 8 illustrates the adjustable second handle of FIG. 4 with anexterior housing removed according to some embodiments.

FIG. 9 illustrates a top section view of the adjustable side handle forthe power tool of FIG. 1 according to some embodiments.

FIG. 10 illustrates a top section view of the adjustable side handle forthe power tool of FIG. 1 according to some embodiments.

FIG. 11 illustrates a perspective view of an interior portion of thepower tool including a side handle locking mechanism and a wire routingchannel according to some embodiments.

FIG. 12 illustrates the side handle locking mechanism of the adjustableside handle for the power tool of FIG. 1 according to some embodiments.

FIG. 13 illustrates the side handle locking mechanism of the adjustableside handle for the power tool of FIG. 1 according to some embodiments.

FIG. 14 illustrates wire routing through the side handle lockingmechanism of the adjustable side handle for the power tool of FIG. 1according to some embodiments.

FIG. 15 illustrates a perspective view of a power tool includingtwo-hand control according to some embodiments.

FIG. 16A illustrates a side handle of a power tool of FIG. 15 accordingto some embodiments.

FIG. 16B illustrates a method for detecting operator presence accordingto some embodiments.

FIGS. 17A and 17B illustrate a perspective view of a side handleincluding an electrical connection to a power tool according to someembodiments.

FIG. 17C illustrates a circuit implemented in a power tool for detectingoperator presence according to some embodiments.

FIG. 18 illustrates a flowchart for a detecting a type of attachedcomponent according to some embodiments.

FIG. 19A illustrates a side handle including a side handle electricalconnection according to some embodiments.

FIG. 19B illustrates wire routing through the side handle of FIG. 19Aaccording to some embodiments.

FIG. 19C illustrates wire routing through the side handle of FIG. 19Aaccording to some embodiments.

FIG. 19D illustrates a power tool including a side handle electrical forconnecting to the side handle of FIG. 19A according to some embodiments.

FIG. 19E illustrates wire routing of the power tool of FIG. 19Daccording to some embodiments.

FIG. 20 illustrates a power tool including an autostop functionaccording to some embodiments.

FIGS. 21A and 21B illustrates a perspective view of a power toolincluding loss of control detection according to some embodiments

FIG. 21C illustrates a flowchart for a power tool including loss ofcontrol detection according to some embodiments

FIG. 21D illustrates a flowchart for a power tool including loss ofcontrol detection according to some embodiments.

FIG. 22A illustrates a power tool including an adjustable side handlelocation according to some embodiments.

FIG. 22B illustrates a power tool including an adjustable side handlelocation according to some embodiments.

FIG. 22C illustrates a power tool including an adjustable side handlelocation according to some embodiments.

FIG. 22D illustrates a power tool including an adjustable side handlelocation according to some embodiments.

FIG. 22E illustrates a power tool including an adjustable side handlelocation according to some embodiments.

FIG. 22F illustrates a power tool including an adjustable side handlelocation according to some embodiments.

FIG. 23A-23C illustrate a power tool including component sensingaccording to some embodiments.

FIG. 23D illustrates a flowchart for the power tool of FIGS. 23A-23Caccording to some embodiments.

FIG. 24 illustrates a flowchart for detecting loss of control for apower tool according to some embodiments.

FIG. 25 illustrates a fixed wheel guard according to some embodiments.

FIG. 26A illustrates a guard locking flange according to someembodiments.

FIG. 26B illustrates a roll pin according to some embodiments.

FIG. 27 illustrates a spindle locknut assembly according to someembodiments.

FIG. 28 illustrates a power tool including lanyard integration accordingto some embodiments.

FIG. 29 illustrates a power tool including battery isolation accordingto some embodiments.

FIG. 30 illustrates a power tool including an adjustable side handle inwireless communication with a power tool main housing according to someembodiments.

FIG. 31 illustrates a flowchart for detecting cut-through for a powertool according to some embodiments.

DETAILED DESCRIPTION

FIG. 1 illustrates a power tool, such as a portable rotary power tool,that implements several different methods and systems to control thetool and a motor of the tool. In some embodiments, the portable powertool is a grinder 100. The grinder 100 may include a main tool housing120, a first handle 140 that extends along the main tool housing 120,and a second handle 105 that extends transversely in an outwarddirection from the main tool housing 120. A motor 210 (shown in FIG. 2 )is located within the main tool housing 120. An output shaft 125 iscoupleable to a tool holder that may be configured to receive anaccessory 150, such as a cutting tool, a grinding disc, a rotary burr, asanding disc, etc. Various types of accessories may be interchangeablyattached to the tool holder and may be designed with differentcharacteristics to perform different types of operations. For example,the accessory 150 may be made of a material and have dimensions suitablefor performing a specific type of task. The characteristics of anaccessory may affect the performance of the grinder 100 or may imposeconstraints on operation of the tool. For example, different accessorytypes may be configured to work at different rotational speeds orapplied torques depending on the characteristics of the accessory andthe task to be performed. During operation of the grinder 100, the motorand the output shaft 125 may be controlled to rotate at a wide range ofspeeds.

Due to the wide range of speeds, in some embodiments, the grinder 100may include a guard 130 to protect a user or another object in thesurrounding environment from the different accessory types that may beattached to the tool holder. In some embodiments, the guard 130 preventsa user from contacting the accessory 150. In some embodiments, the guard130 provides protection against, for example, sparks.

In some embodiments, the first handle 140 may define a battery packreceptacle 145, which is positioned on an end of the first handle 140opposite the main tool housing 120. The battery pack receptacle 145 isconfigured to selectively, mechanically, and electrically connect to arechargeable battery pack (i.e., a power supply) for powering the motor210. The battery pack is insertable into or attachable to the batterypack receptacle 145. The battery pack may include any of a number ofdifferent nominal voltages (e.g., 12V, 18V, 24V, 36V, 40V, 48V, etc.),and may be configured having any of a number of different chemistries(e.g., lithium-ion, nickel-cadmium, etc.). In some embodiments, themotor 210 may be powered by a remote power source (e.g., an ACelectrical outlet) through a power cord and a power interface of thegrinder 100. The first handle 140 further contains control electronicsfor the grinder 100.

The second handle 105 may allow a user to better control the operationof the grinder 100. In some embodiments, the first handle 140 and/or thesecond handle 105 include a variety of sensors to detect differentoperational characteristics and/or user characteristics (e.g., operatorpresence, grip pressure, etc.). For example, the first handle 140includes a first sensor 160 for detecting the presence of a user's handon the first handle 140, and the second handle 105 includes a secondsensor 165 for detecting the presence of a user's second hand on thesecond handle 105. In some embodiments, the sensors 160, 165 arepressure sensors that detect the presence of a minimum grip pressure onthe handles 140, 105. Various signals from the sensors located in thesecond handle 105 may be sent to the grinder 100's main control systemand the operation of the motor 210 may be controlled based on thesignals (e.g., enabling or disabling the motor 210, modifying a torquelimit, etc.).

The second handle 105 includes a pivot mechanism 103. The pivotmechanism 103 enables the second handle 105 to pivot with respect to apivot arm 108. The pivot mechanism 103 permits the second handle 105 tobe pivoted through a plurality of different positions relative to thepivot arm 108. For example, the second handle is positioned at azero-degree angle, or parallel relative to the main tool housing 120 ofthe grinder 100 (e.g., substantially parallel to the main tool housing120). The second handle 105 can also be moved to another position, suchas substantially perpendicular to the main tool housing 120 (e.g., at a90-degree angle). In some embodiments, the second handle 105 can bepositioned at five discrete positions using the pivot mechanism 103. Inother embodiments, greater or fewer discrete positions are available forthe second handle.

The pivot arm 108 allows the second handle 105 to be pivoted into aplurality of different positions around the circumference of the maintool housing 120. For instance, the pivot arm 108 may rotate into afirst pivot position, such as a left-handed position as illustrated inFIG. 1 , or a second pivot position, such as a right-handed position. Insome embodiments, the second handle 105 may be pivoted to berespectively above the main tool housing 120 and substantiallyperpendicular to left-handed and right-handed positions (e.g.,perpendicular to a cutting plane of the grinder 100). Other embodimentsmay include additional pivot positions for the second handle 105. Oncethe second handle 105 is rotated into one of the plurality of pivotpositions, the pivot arm 108 can be secured in place by a lockingmechanism 113, as described in greater detail below.

FIG. 2 illustrates a side section view of the grinder 100. In someembodiments, a controller 200 (e.g., located on a printed circuit board)is located within the first handle 140. In some embodiments, varioussensors 205 may also be located within the first handle 140. The outputshaft 125 protrudes downwards, towards a potential workpiece. In someembodiments, the accessory 150 (e.g., a grinder blade) may be attachedto the output shaft 125. Because an accessory 150, such as a grinderblade, is potentially hazardous to the user and the area surrounding thegrinder, the guard 130 is also attached to the output shaft 125 andprotrudes downward towards a workpiece and extends around the blade 150.This provides protection from the blade 150 and any potential debristhat is produced during operation.

In some embodiments, the motor 210 is located between the output shaft125 and the battery pack receptacle 145, and beneath a trigger 155within the main tool housing 120. The trigger 155 is used to control themotor 210, which receives control signals from the controller 200 tocontrol the output shaft 125 and other aspects of the grinder 100.

In some embodiments, the grinder 100 incudes a guard presence sensor 215for detecting the presence of the guard 130. In some embodiments, thegrinder 100 is prevented from operating (e.g., motor 305 is preventedfrom operating) when the guard presence sensor 215 does not detect theguard 130. The grinder 100 also includes a component type indicator 220.The component type indicator 220 is configured to provide an indicationto the grinder 100 of the type of component (e.g., guard 130) that isconnected to the grinder. For example, guards of different sizes mayresult in the grinder 100 operating differently. Although the componenttype indicator 220 is illustrated with respect to the guard 130, thecomponent type indicator can additionally or alternatively be associatedwith another component of the grinder 100, such as the second handle105, a dust hood, the accessory 150, etc.

The first handle 140 includes the switch or trigger 155 operable toelectrically connect the power source (e.g., the battery pack) and themotor 210. In some embodiments, the trigger 155 may be a “lock-off”trigger having a paddle member and a lock-off member 208 supported bythe paddle member. The paddle member is operable to actuate a switch 203electrically connected to the controller 200. The switch 203 isconfigured to control selective activation and deactivation of the motor210 during operation of the grinder 100. The lock-off member 208 isconfigured to selectively prevent operation of the paddle member (e.g.,prevent activation of the switch 203). In some embodiments, the paddlemember acts as the detection for a user's first hand on the first handle140. In other embodiments, a user's hand is detected using other sensors(e.g., grip sensors, pressure sensors, touch sensors, electromechanicalsensors, etc.).

FIG. 3 illustrates a control system for the grinder 100. The controlsystem includes a controller 300. The controller 300 is electricallyand/or communicatively connected to a variety of modules or componentsof the grinder 100. For example, the illustrated controller 300 iselectrically connected to a motor 305 (e.g., motor 210), a battery packinterface 310, a trigger switch 315 (connected to a trigger 320), one ormore sensors or sensing circuits 325, one or more indicators 330, a userinput module 335, a power input module 340, and a FET switching module350 (e.g., including a plurality of switching FETs). The controller 300includes combinations of hardware and software that are operable to,among other things, control the operation of the grinder 100, monitorthe operation of the grinder 100, activate the one or more indicators330 (e.g., an LED), etc.

The controller 300 includes a plurality of electrical and electroniccomponents that provide power, operational control, and protection tothe components and modules within the controller 300 and/or the grinder100. For example, the controller 300 includes, among other things, aprocessing unit 355 (e.g., a microprocessor, a microcontroller, anelectronic processor, an electronic controller, or another suitableprogrammable device), a memory 360, input units 365, and output units370. The processing unit 355 includes, among other things, a controlunit 375, an arithmetic logic unit (“ALU”) 380, and a plurality ofregisters 385, and is implemented using a known computer architecture(e.g., a modified Harvard architecture, a von Neumann architecture,etc.). The processing unit 355, the memory 360, the input units 365, andthe output units 370, as well as the various modules or circuitsconnected to the controller 300 are connected by one or more controland/or data buses (e.g., common bus 390). The use of one or more controland/or data buses for the interconnection between and communicationamong the various modules, circuits, and components would be known to aperson skilled in the art in view of the embodiments described herein.

The memory 360 is a non-transitory computer readable medium andincludes, for example, a program storage area and a data storage area.The program storage area and the data storage area can includecombinations of different types of memory, such as a ROM, a RAM (e.g.,DRAM, SDRAM, etc.), EEPROM, flash memory, a hard disk, an SD card, orother suitable magnetic, optical, physical, or electronic memorydevices. The processing unit 355 is connected to the memory 360 andexecutes software instructions that are capable of being stored in a RAMof the memory 360 (e.g., during execution), a ROM of the memory 360(e.g., on a generally permanent basis), or another non-transitorycomputer readable medium such as another memory or a disc. Softwareincluded in the implementation of the grinder 100 can be stored in thememory 360 of the controller 300. The software includes, for example,firmware, one or more applications, program data, filters, rules, one ormore program modules, and other executable instructions. The controller300 is configured to retrieve from the memory 360 and execute, amongother things, instructions related to the control processes and methodsdescribed herein. In other constructions, the controller 300 includesadditional, fewer, or different components.

The motor 305 includes a rotor and a stator that surrounds the rotor. Insome embodiments, the motor 305 is a brushless direct current (“BLDC”)motor in which the rotor is a permanent magnet rotor and the statorincludes coil windings that are selectively energized to drive therotor. In other embodiments, the motor is a brushed motor. The stator issupported within the main tool housing 120 and remains stationaryrelative to the main tool housing 120 during operation of the grinder100. The rotor is rotatably fixed to a rotor shaft and configured torotate with the rotor shaft, relative to the stator, about a motor axis.A portion of the rotor shaft is associated with or corresponds to theoutput shaft 125 extending from the main tool housing 120. In someembodiments, the motor 305 is an outer rotor motor.

The battery pack interface 310 includes a combination of mechanicalcomponents (e.g., rails, grooves, latches, etc.) and electricalcomponents (e.g., one or more terminals) configured to and operable forinterfacing (e.g., mechanically, electrically, and communicativelyconnecting) the grinder 100 with a battery pack. For example, powerprovided by the battery pack to the grinder 100 is provided through thebattery pack interface 310 to the power input module 340. The powerinput module 340 includes combinations of active and passive componentsto regulate or control the power received from the battery pack prior topower being provided to the controller 300. The battery pack interface310 also supplies power to the FET switching module 350 to provide powerto the motor 305. The battery pack interface 310 also includes, forexample, a communication line 395 for provided a communication line orlink between the controller 300 and the battery pack.

The indicators 330 include, for example, one or more light-emittingdiodes (“LEDs”). The indicators 330 can be configured to displayconditions of, or information associated with, the grinder 100. Forexample, the indicators 330 are configured to indicate measuredelectrical characteristics of the grinder 100, the status of the grinder100, etc. The user input module 335 is operably coupled to thecontroller 300 to, for example, select a forward mode of operation or areverse mode of operation, a torque and/or speed setting for the grinder100 (e.g., using torque and/or speed switches), etc. In someembodiments, the user input module 335 includes a combination of digitaland analog input or output devices required to achieve a desired levelof operation for the grinder 100, such as one or more knobs, one or moredials, one or more switches, one or more buttons, etc.

The controller 300 is configured to determine whether a fault conditionof the grinder 100 is present and generate one or more control signalsrelated to the fault condition. For example, the sensing circuits 325include one or more current sensors, one or more speed sensors, one ormore Hall Effect sensors, one or more temperature sensors, anaccelerometer, a gyroscope, an inertial measurement unit [“IMU”], one ormore pressure sensors, one or more object presence sensors, etc. Thecontroller 300 calculates or includes, within memory 360, predeterminedoperational threshold values and limits for operation of the grinder100. For example, when a potential thermal failure (e.g., of a FET, themotor 305, etc.) is detected or predicted by the controller 300, powerto the motor 305 can be limited or interrupted until the potential forthermal failure is reduced. If the controller 300 detects one or moresuch fault conditions of the grinder 100 or determines that a faultcondition of the grinder 100 no longer exists, the controller 300 isconfigured to provide information and/or control signals to anothercomponent of the grinder 100 (e.g. the battery pack interface 310, theindicators 330, etc.).

FIG. 4 and FIG. 5 are illustrations of partial views of the secondhandle 105 of the grinder 100, according to some embodiments. The secondhandle 105 incudes a first over-mold portion 403 positioned on thesecond handle 105 and configured to protect internal components of thesecond handle 105 from water, dust, or other unwanted foreign debris.The second handle 105 also includes a second over-mold portion,positioned opposite the first over-mold portion 405 (see FIG. 8 ). Thepivot arm 108 of the second handle 105 includes locking mechanism 408configured to mechanically couple with the pivot mechanism 103.

FIG. 6 and FIG. 7 are illustrations of the second handle 105 of thegrinder 100 with an outer housing removed. The second handle 105includes an internal cavity 505. The second handle 105 includes aprinted circuit board (“PCB”) 603 (e.g., a flexible printed circuitboard) which includes a microswitch sensor 608 positioned on the PCB. Insome embodiments, the PCB 603 is folded or molded around the outercircumference 515 of the second handle 105. The microswitch sensor 608is configured to mechanically contact the first over-mold portion 403.Additionally, the microswitch sensor 608 is configured to detect thepresence of a hand. For example, when a user grips the second handle 105with sufficient grip force (e.g., to overcome a spring force biasing thefirst over-mold portion 403 away from the microswitch sensor 608), thefirst over-mold portion 403 is depressed and the microswitch sensor 608is activated. In some embodiments, a grip force above a threshold valueis required for the grinder 100 to detect hand presence. In otherembodiments, a user's hand is detected merely by detecting a user's handtouching the second handle 105. The microswitch sensor 608 then sends asignal to the controller 200. In some embodiments, the microswitchsensor 608 acts as a secondary trigger mechanism. For example, in someembodiments, the microswitch sensor 608 must be activated prior to theactivation of the trigger 155 in order for the grinder to operate. Insome embodiments, there is an activation time associated with theoperation of the trigger 155 after a user grips the second handle 105.For example, in some embodiments, the trigger 155 must be activatedwithin a predetermined time period after a user's grip has been detectedby the microswitch sensor 608.

The internal cavity 505 includes wires 613 for connecting themicroswitch sensor 608 to the controller 200. In some embodiments, thewires 613 are routed around support structures 618 for the second handle105. The support structures 618 are configured to, for example, maintainthe structural integrity of the internal cavity 505 during use of thesecond handle 105. The wires 613 are configured to exit the secondhandle 105 through a first channel 623 through the locking mechanism408.

The locking mechanism 408 is configured to engage the pivot mechanism103 to move the second handle 105 to a plurality of different position.The locking mechanism includes a spring 628 to bias the lockingmechanism 408 toward the pivot mechanism 103. In order to pivot thesecond handle 105 with respect to the pivot mechanism 103, a user wouldhave to pull the second handle 105 away from the pivot mechanism 103 andagainst the bias force of the spring 628. A body portion 633 that formsthe first channel 623 also includes ribs or projections 638. Theprojections 638 prevent the second handle 105 from rotating with respectto the pivot mechanism 103. When the locking mechanism 408 clears teeth643 of the pivot mechanism 103 after being pulled away from the pivotmechanism 103, the second handle 105 can be pivoted to a differentposition with respect to the pivot mechanism 103.

FIG. 8 is an illustration of an interior portion of the second handle105 of the grinder 100. In this illustration, portions of the secondhandle 105 are removed in order to illustrate the first over-moldportion 403 and a second over-mold portion 803. The second over-moldportion 803 is positioned opposite the first over-mold portion 403.Either the first over-mold portion 403 or the second over-mold portion803 can activate the microswitch sensor 608. For example, depending onthe position of the second handle (e.g., right or left side of thegrinder 100), one of the first over-mold portion 403 and the secondover-mold portion 803 would correspond to a top portion of the secondhandle 105. In some embodiments, both the first and second over-moldportions 403, 803 need to be pressed to activate the microswitch sensor608 and operate the grinder 100. In some embodiments, the second handleincludes a second microswitch sensor 608 for the second over-moldportion 803. Wires 613 are routed around a screw 808 associated with thesupport structures 618 and into the first channel 623. In someembodiments, the first over-mold portion 403 and the second over-moldportion 803 are mechanically connected to the microswitch sensor 608.The second handle 105 additionally includes the projections 638 forrotationally locking the second handle 105 with respect to the pivotmechanism 103. The projections 638 prevent twisting of the second handle105 relative to pivot mechanism 103.

FIG. 9 and FIG. 10 are illustrations of an internal wire routing portionof the second handle 105 and the grinder 100. The wires 613 run from theinternal cavity 505 of the second handle 105 into the first channel 623,and then into a second channel 903 in the pivot mechanism 103. The wires613 run from the second channel 903 into a third channel 908 within thepivot arm 108. The second channel 903 and the third channel 908 areconfigured to route the wires 613 such that the wires 613 do notinterfere with the pivoting of the pivot mechanism 103 or the rotationof the pivot arm 108. As a result, the second channel 903 and thirdchannel 908 prevent the wires 613 from bundling/crimping when the secondhandle 105 is pivoted with respect to the pivot mechanism 103 or thepivot arm 108 is rotated with respect to the grinder 100. A wire path913 for routing the wires 613 from the second handle 105 to the maintool housing 120 is illustrated in FIG. 14 . In the embodimentillustrated in FIG. 10 , the second handle 105 is positioned at a45-degree angle relative to the pivot arm 108.

FIG. 11 illustrates an interior portion of the grinder 100 associatedwith the routing of the wires 613. In some embodiments, the thirdchannel 908 extends into and terminates in a main housing cavity 1103 ofthe main tool housing 120. The main tool housing 120 houses the motor,controller, and other such components of the grinder 100 that are notillustrated in FIG. 11 . In some embodiments, the main housing cavity1103 includes a fourth channel 1108 configured proximate to, andextending orthogonally from, the third channel 908. The fourth channel1108 is configured to receive the wires 613 from the third channel 908and route the wires 613 along the length of the fourth channel 1108(e.g., around a gearcase of the grinder 100). The wires 613 terminate inor after the fourth channel 1108 at a first electrical connector (notillustrated). In some embodiments, the first connector is configured toelectrically and mechanically connect with a main wire harness of thepower tool to connect the wires 613 to the controller 200. In someembodiments, the first connector is configured to connect to a secondconnector (not illustrated) that extends from the controller 200 of thegrinder 100. In some embodiments, the wires 613 extend all the way tothe controller 200 without a first or second connector. In someembodiments, the grinder 100 includes additional channels or alternativewire routing paths.

FIG. 12 and FIG. 13 illustrate the operation of the locking mechanism113 for the pivot arm 108 of the grinder 100, according to someembodiments. The locking mechanism 113 is configured to lock the pivotarm 108 into one of a plurality of pivot positions. In some embodiments,the locking mechanism 113 a button, a switch, a lever, or the like, thatis biased into a locked position. Once locked by the locking mechanism113, the pivot arm 108 is secured in place and cannot be moved toanother pivot position. In some embodiments, the pivot arm 108 includesa pivot joint 1203 in contact with the main tool housing 120 of thegrinder 100. A first bushing 1208 is mechanically connected to the pivotjoint 1203. The first bushing 1208 is configured to support the pivotjoint 1203. In some embodiments, a second bushing 1213 opposite thefirst bushing 1208 is also used to support the pivot joint 1203. Thepivot joint 1203 is configured to mechanically connect the pivot arm 108with the locking mechanism 113. The pivot joint 1203 includes a firstaperture or first groove 1218 configured to mechanically couple with atooth or projection 1223 of the locking mechanism 113. When theprojection 1223 is mechanically coupled to the first groove 1218, thepivot arm 108 is locked into position by the locking mechanism 113. Insome embodiments, the first groove 1218 is associated with the first orleft-handed pivot position. The pivot joint 1203 also includes a secondaperture or second groove 1228 associated with a second or right-handedpivot position. The projection 1223 is configured to mechanicallyconnect to the second groove 1228 to lock the pivot arm 108 into thesecond pivot position. The pivot joint 1203 further includes a thirdaperture or third groove 1233 associated with a third or middle positionfor the pivot arm 108. The projection 1223 is configured to mechanicallyconnect to the third groove 1233 to lock the pivot arm 108 into thethird pivot position. In some embodiments, the pivot joint 1203 includesadditional apertures or grooves associated with additional pivotpositions. In some embodiments, the locking mechanism 113 includes oneor more springs 1238 configured to bias the projection 1223 toward oneof the first groove 1218, the second groove 1228, or the third groove1233.

FIG. 14 is an illustration of an internal wire routing portion of thesecond handle and the grinder 100. The wire path 913 routes the wires613 from the second handle 105 to the main tool housing 120. The wires613 run from the internal cavity 505 of the second handle 105 into thefirst channel 623, and then into a second channel 903 in the pivot arm108. The wires 613 run from the second channel 903 into a third channel908 within the pivot arm 108. The second channel 903 and the thirdchannel 908 are configured to route the wires 613 such that the wires613 do not interfere with the pivoting of the pivot mechanism 103 or therotation of the pivot arm 108. As previously described, in someembodiments the wires may be configured to electrically and mechanicallyconnect with a main wire harness of the power tool to connect the wires613 to the controller 200. In some embodiments, the wires 613 connectdirectly to the controller 200.

FIG. 15 illustrates an embodiment of the grinder 100 including atwo-handed control feature. The grinder 100 includes the first handle140 for the user to grip with one hand, and a second handle 105 for theuser to grip with another hand. In some embodiments, for the grinder 100to operate, the first handle 140 and/or the second handle 105 include avariety of sensors to detect different operational characteristicsand/or user characteristics (e.g., operator presence, grip pressure,etc.). For example, the first handle 140 includes a first sensor 160 fordetecting the presence of a user's hand on the first handle 140, and thesecond handle 105 includes a second sensor 165 for detecting thepresence of a user's second hand on the second handle 105. In someembodiments, the sensors 160, 165 are pressure sensors that detect thepresence of a minimum grip pressure on the handles 140, 105. Varioussignals from the sensors located in the second handle 105 may be sent tothe grinder 100's main control system, and the operation of the motor210 may be controlled based on the signals (e.g., enabling or disablingthe motor 210, modifying a torque limit, etc.).

In another embodiment, the sensors 160, 165 are capacitive sensors thatdetect the presence of the user's hands on or near the handles 140, 105.In other embodiments, the sensors 160, 165 are microswitches that detectthe presence of the user's hands on the handles 140, 105. In anotherembodiment, the sensors 160, 165 are photolight sensors that areconfigured to detect the adjustment of light based on the position ofthe users hand on the handles 140, 105 (e.g., no light detectedindicates hand presence).

In some embodiments, the grinder 100 includes one sensor, such as secondsensor 165. The second sensor 165 (e.g., pressure sensor, capacitivesensor, microswitch, photolight sensor, etc.) is located in the secondhandle 105 to detect the presence of a user's second hand. The user usesthe other hand to grip the first handle 140 and pull the main trigger170 to operate the grinder 100. The sensor 165 must detect the presenceof one of the user's hands in addition to compressing the main trigger170 in order for a signal to be sent to the grinder 100's main controlsystem, and the operation of the motor 210 may be controlled based onthe signals (e.g., enabling or disabling the motor 210, modifying atorque limit, etc.).

FIG. 16A illustrates a perspective view of the second handle 105. Insome embodiments, the grinder 100 will only operate if a user isoperating the grinder 100 by gripping both the first handle 140 and thesecond handle 105. In some embodiments, the first handle 140 may supporta switch or trigger 155 operable to selectively electrically connect thepower source (e.g., the battery pack) and the motor 305. In someembodiments, the trigger 155 may be a “lock-off” trigger having a paddlemember and a lock-off member supported by the paddle member. The paddlemember is operable to actuate a microswitch to selectively activate anddeactivate the motor during operation of the grinder 100. The lock-offmember selectively prevents operation of the paddle member.Specifically, the lock-off member is pivotable to selectively lock andunlock the paddle member. The speed of the motor may be controlled byvarying the level of depression of the paddle member. In someembodiments, the paddle member acts as the detection for a user's firsthand on the first handle 140. In other embodiments, a first forcesensitive resistor is located on the first handle 140 and is configuredto detect pressure (e.g., from a user's first hand). In otherembodiments, a user's hand is detected using other sensors (e.g., gripsensors, pressure sensors, touch sensors, electromechanical sensors,etc.).

The second handle 105 includes an internal surface which includes aninternal cavity 505. In some embodiments, the internal cavity 505remains hollow throughout the length of the second handle 105. In someembodiments, the second handle 105 includes a flexible printed circuitboard (“PCB”) 510 which includes a force sensitive resistor printed onthe PCB 510. The PCB is folded or molded around an outer circumference515 of the second handle 105. The force sensitive resistor may beconfigured to detect a relatively light pressure (e.g., by a hand). Inother embodiments, a grip force above a threshold value is required forthe grinder to detect hand presence. In other embodiments, a user's handis detected using other sensors (e.g., pressure sensors, touch sensors,electromechanical sensors, etc.).

FIG. 16B illustrates a method 600 for allowing use of the grinder 100.When a user indicates an intention to use the grinder 100, the grinder100 detects a pick-up of the grinder 100 but the grinder 100 isprohibited from operating (STEP 605). The method 600 then includeschecking if the user's first hand is detected on the first handle 140(STEP 610). If the first hand is not detected on the first handle 140,the user is prohibited from using the grinder 100. If the user's firsthand is detected, the method 600 then includes checking to see if theuser's second hand is detected on the second handle 105 (STEP 615). Ifthe second hand is not detected on the second handle 105, the user isprohibited from using the grinder 100. If the user's second hand isdetected to be located on the second handle 105, the controller 300allows operation of the grinder 100 (STEP 620). As previously described,in some embodiments, there is an activation time associated with theoperation of the trigger after a user grips the second handle. Forexample, in some embodiments, the trigger must be activated within apredetermined time period after a user's grip has been detected. In someembodiments, the controller 300 allows operation of the grinder 100immediately.

In some embodiments, the grinder 100 includes an electrical connectionto an accessory device (e.g., a second handle). The grinder 100 includesthe main tool housing 120 that includes the first handle 140 for beinggripped by a user. The grinder 100 also includes an accessory deviceattachment portion on the main tool housing 120. The accessory deviceattachment portion includes, for example, a threaded hole that canreceive an accessory (e.g., having a threaded stud). The accessorydevice attachment portion is configured to receive an accessory devicesuch as the second handle 105 to provide a second hand grip for a user.When the accessory device is attached to the grinder 100, an electricalconnection is provided between the grinder 100 and the accessory device.As a result of this electrical connection, power is provided to theaccessory device for powering one or more circuits (e.g., sensors,outputs, etc.) of the accessory device.

For example, FIG. 17A illustrates an embodiment of the electricalconnection of the accessory device. In this embodiment, the accessorydevice is illustrated as second handle 105. The second handle 105includes a first electrical contact 1710 located on a threaded stem1725, and a second contact 1705. In some embodiments, the second contact1705 is a metal annular ring positioned on the second handle 105, and isconfigured to contact a corresponding electrical contact located on themain tool housing 120. Once the first electrical contact 1710 and thesecond contact 1705 have made proper connections with their counterpartson the main tool housing 120 (e.g., the second handle 105 is fullyscrewed down), a sensor (e.g., the force sensitive resistor) will beable to begin sensing on the second handle 105.

FIG. 17B illustrates another embodiment of the electrical connection ofthe accessory device. In this embodiment, the accessory device isillustrated as the second handle 105. The second handle 105 includes afirst electrical contact 1715 and a second contact 1720, which are metalannular rings positioned on the second handle 105. Once the firstelectrical contact 1715 and the second contact 1720 have made properconnections with their counterparts on the main tool housing 120 (e.g.,the second handle 105 is fully screwed down), a sensor (e.g., the forcesensitive resistor) will be able to begin sensing on the second handle105. In some embodiments, the electrical connection of the accessorydevice would be a wireless connection between the main tool housing 120and the accessory device. For example, an inductive or capacitivecoupling can be used to wirelessly transmit power to the accessorydevice. Such a configuration enables a water-tight seal between thegrinder 100 and the accessory device.

FIG. 17C illustrates a schematic 1750 for the electrical connection ofthe accessory device to the grinder 100. The schematic 1750 includes asensor 1755 (e.g., a force sensitive resistor), a gearcase 1760, and thecontroller 300. An electrical connection 1765 is made between thegrinder 100 and the second handle 105 using, for example, the connectiontechniques described above with respect to FIGS. 17A and 17B. Thecontroller 300 monitors the resistance of the force sensitive resistorto detect, for example, the presence or absence of a user's hand.

FIG. 18 illustrates a method 1800 for the grinder 100 that detects atype of component connected to the grinder 100 (STEP 1805). For example,the grinder 100 can detect a particular type of disk guard, a particulartype of dust hood, etc. The detection of the particular type ofcomponent connected to the grinder 100 can be achieved using a sensor(e.g., an induction coil sensor, a Hall effect sensor, an opticalsensor, wireless communication, etc.). In some embodiments, the sensoris configured to detect a passive characteristic of the component (e.g.,read a bar code, serial number, QR code, etc.). In other embodiments,the component can provide information to the grinder (e.g., using thecomponent type indicator 220). In some embodiments, the component typeindicator 220 is an RFID tag. In other embodiments, the component typeindicator 220 includes a power source and is configured to communicatewith the grinder 100 (e.g., using a short-range communication protocol,such as Bluetooth).

The sensor provides an output to the controller 300 of the grinder 100(STEP 1810). The controller 300 can then determine the type of attachedcomponent based on the output of the sensor (STEP 1815). In someembodiments, the controller 300 looks up a characteristic of thecomponent (e.g., a bar code, serial number, QR code, etc.) to determinethe type of component. In other embodiments, information received fromthe component includes an indication of the type of component attachedto the grinder 100. After the grinder 100 determines the particular typeof component connected to the grinder 100, the grinder 100 can take acontrol action based on the detected type of component connected to thegrinder (e.g., adjust a torque or speed setting) (STEP 1820).

FIG. 19A illustrates an embodiment of an electrical connection of anaccessory device 1945. In this embodiment, the accessory device 1945 isillustrated as the second handle 105. The second handle 105 includesspring loaded contacts 1905. The spring loaded contacts 1905 are used toform the electrical connection from the second handle 105 to the maintool housing 120. The spring loaded contacts 1905 are mounted, forexample, on a printed circuit board (“PCB”) 1940 located within anaccessory device 1945 of the second handle 105. The accessory device1945 includes an aperture or hole 1950 on a surface of the accessorydevice 1945. The PCB 1940 is mounted on the surface of the accessorydevice 1945 that includes the hole 1950. The spring loaded contacts 1905are positioned on the PCB 1940 to be accessible through the hole 1950.

In some embodiments, the grinder 100 includes a plurality of rails 1955(see FIG. 19D) located on the side of the main tool housing 120 (asshown in FIG. 19D). The plurality of rails 1955 of the grinder 100 areused to attach to a plurality of rails 1910 of the second handle 105.The rails 1910 slide directly on the rails of the grinder 100,mechanically connecting the grinder 100 and the second handle 105.

When the grinder 100 and the second handle 105 are connected to oneanother, the spring loaded contacts 1905 are then coupled to acorresponding electrical contact 1935 located on the main tool housing120. Once the spring loaded contacts 1905 have made electricalconnection with their counterparts on the main tool housing 120 (e.g.,the second handle 105 has attached rails 1910 with the correspondingrails of the main tool housing 120), a sensor (e.g., pressure sensor,capacitive sensor, microswitch, photolight sensor, etc.) will be able tobe used to sense the second handle 105 and a user's hand.

FIG. 19B illustrates an interior of the accessory device 1945. Theaccessory device 1945 is illustrated as the second handle 105. Thesecond handle 105 includes the spring loaded contacts 1905. In someembodiments, the accessory device 1945 includes a pivoting mechanism1930. The pivoting mechanism 1930 allows the second handle 105 to rotatewith respect to the grinder 100, while the accessory device 1945 remainssecurely attached and electrically connected to the main tool housing120. In some embodiments, the accessory device 1945 includes extra spaceextending from the second handle 105 to the PCB 1940. This extra spaceallows wire to coil as the second handle 105 is adjusted. In someembodiments, the extra space includes a channel 1915 for the extra wireto travel to. For example, as the second handle 105 rotates with respectto the accessory device 1945 via the pivoting mechanism 1930, the extrawire extends and retracts based on the positioning of the second handle105.

FIG. 19C illustrates another view of the electrical connection of theaccessory device 1945. In some embodiments, the accessory device 1945includes the pivoting mechanism 1930. To allow the wires 1960 to movewith the pivoting mechanism 1930, the extra space includes the channel1915 for the wire to extend from the second handle 105 to the PCB 1940.The channel 1915 is curved around the pivoting mechanism 1930, allowingfor the extra wire to travel around the pivoting mechanism 1930 and notinterfere with the rotation of the pivoting mechanism 1930.

FIG. 19D illustrates the electrical connection of the grinder 100 to thesecond handle 105. As previously noted, the main tool housing 120includes an accessory device interface. The accessory device interfaceincludes a plurality of rails 1955 that are attached to the plurality ofrails 1910. Once the second handle 105 is attached to the main toolhousing 120, a plurality of electrical contacts 1935 are configured tocome into contact with the corresponding spring loaded contacts 1905.When the plurality of electrical contacts 135 and the spring loadedcontacts 1905 have made electrical connection, a sensor (e.g., pressuresensor, capacitive sensor, microswitch, photolight sensor, etc.) will beable to begin sensing on the second handle 105 and a user's hand.

FIG. 19E illustrates electrical connections of the grinder 100 to thesecond handle 105. In some embodiments, the second handle 105 may beelectrically and mechanically connected to either side of the grinder100. Furthermore, because the second handle 105 can be connected toeither side of the grinder 100, there is a set of mechanical componentson either side of the grinder 100. For example, the mechanicalcomponents include rails 1955 for the rails 1910 of the second handle105 to firmly attach to. In addition to the mechanical components, thereare also electrical contacts 1935 on either side of the grinder so thatan electrical connection may be made from the second handle 105 and thegrinder 100. In some embodiments, a plurality of wires 1970 extend fromthe grinder 100's main control system to the plurality of electricalcontacts 1935 of the grinder 100. Two sets of the plurality of wires1970 extend from the main control system, one set of the plurality ofwires 1970 extend to one side of the grinder 100 and the other set ofthe plurality of wires 1970 extend to the other side of the grinder 100.When the second handle 105 is attached to either or both sides of thegrinder 100, the plurality of electrical contacts 1935 on either side ofthe grinder 100 are configured to come into contact with thecorresponding spring loaded contacts 1905 of the handle 105. When theplurality of electrical contacts 1935 and the spring loaded contacts1905 have made electrical connection, a sensor (e.g., pressure sensor,capacitive sensor, photolight sensor, etc.) will be able to beginsensing on the second handle 105 and a user's hand.

FIG. 20 illustrates a grinder 2000 that includes a loss of controlmitigation system. In some embodiments, the grinder 2000 includes someor all of the previously described features of the grinder 100. Thegrinder 2000 includes a loss of control module. The loss of controlmodule includes a sensor (e.g., an accelerometer, a gyroscope, aninertial measurement unit [“IMU”]) and is configured to detect linearand/or rotational motion of the grinder 2000. In some embodiments, theloss of control module is located in a first position 2005. The firstposition 2005 couples the loss of control module to the main controlsystem. The main control system is located within the first handle 140between the main tool housing 120 and the battery pack interface 310. Insome embodiments, by coupling the loss of control module with the maincontrol system of the grinder 2000, the loss of control module will beslightly tilted relative to a longitudinal axis of the grinder 2000(i.e., the cutting plane of the blade 150).

In another embodiment, the loss of control module is located in a secondposition 2010. The second position 2010 locates the loss of controlmodule in the area of the guard presence sensor 215 described above. Theguard presence sensor 215 is located near the front of the grinder 2000,above the disk guard 130 so that, when the guard presence sensor 215 iscoupled to the loss of control module, the loss of control module willbe close to the front of the grinder 2000. In the second position, theloss of control module is parallel to the longitudinal axis of thegrinder 2000 (i.e., the cutting plane of the blade 150).

FIGS. 21A and 21B illustrate a grinder that includes a loss of controlmitigation system. The grinder 100 includes at least one sensor located,for example, within the main tool housing 120. The at least one sensoris configured to detect a motion of the grinder 100 indicative of a lossof control of the grinder 100.

In some embodiments, as illustrated in FIG. 21A, a sensor (e.g., anaccelerometer, a gyroscope, an inertial measurement unit [“IMU”]) isconfigured to detect linear motion of the grinder 100. The linear motionmay be described as a forward motion or a reverse motion with respect toa workpiece 199. In other embodiments, the linear motion may bedescribed as lateral to the workpiece 199. If the linear motion, asdetected by the sensor, exceeds a predetermined threshold, a loss ofcontrol is determined. In some embodiments, when the loss of control isdetermined, the grinder 100 is configured to brake the motor 305.

In other embodiments, as illustrated in FIG. 21B, a sensor (e.g., anaccelerometer, a gyroscope, an inertial measurement unit [“IMU”]) isconfigured to detect a rotation of the grinder 100. The rotation of thegrinder 100 may be described as an upward or vertical motion withrespect to a workpiece 199. In another embodiment, the rotation of thegrinder 100 may be described as a rotation about the battery packreceptacle 145. If the rotational motion, as detected by the sensor,exceeds a predetermined threshold, a loss of control is determined. Insome embodiments, when the loss of control is determined, the grinder100 is configured to brake the motor 305.

FIG. 21C shows a method 2100 for detecting a loss of control conditionof the grinder 100. When a user initiate use of the grinder 100 (STEP2105), work on a workpiece begins. The method 2100 includes detectinglinear motion (STEP 2110) as detected from a sensor (e.g., anaccelerometer, a gyroscope, an inertial measurement unit [“IMU”]). Ifthe linear motion detected by the sensor exceeds a linear loss ofcontrol threshold (STEP 2115), the motor 305 of the grinder 100 isstopped (e.g., braked). If the linear motion detected does not exceedthe linear loss of control threshold, the method 2100 then includesdetecting rotational motion of the grinder 100 (STEP 2125). If therotational motion of the grinder 100 exceeds a rotational loss ofcontrol threshold (STEP 2130), the motor 305 of the grinder 100 isstopped (e.g., braked). If the rotational motion of the grinder 100 doesnot exceed the rotational loss of control threshold, the method 2100restarts, providing a constant monitoring of a loss of controlmitigation method. In some embodiments, both linear and rotationalmotion are detected and monitored for the loss of control conditionsimultaneously. In some embodiments, rotational motion is monitoredprior to linear motion of the grinder 100.

FIG. 21D shows a method 2150 for detecting a loss of control conditionof the grinder 100. When a user initiates use of the grinder 100 (STEP2155), work on a workpiece begins. The method 2150 includes detectinglinear motion (STEP 2160) as detected from a sensor (e.g., anaccelerometer, a gyroscope, an inertial measurement unit [“IMU”]). Themethod 2150 includes detecting rotational motion (STEP 2165) as detectedfrom a sensor (e.g., an accelerometer, a gyroscope, one or more Halleffect sensors, or the like). The method 2150 further includesincrementing a linear and rotation accumulator (STEP 2170) based upon athreshold level. For example, if the linear motion detected in STEP 2160exceeds a first threshold and/or the rotational motion detected in STEP2165 exceeds a second threshold, the accumulator will increment. In someexamples, the accumulator increments based upon both a linear motionthreshold and a rotational motion threshold. In some examples, thelinear motion and the rotational motion have separate accumulators thatincrement independently. If the accumulator has reached a predeterminedmaximum value at STEP 2175, the motor 305 of the grinder 100 is stopped(e.g. braked) (STEP 2180). On the other hand, if the accumulator has notreached a predetermined maximum value, the method 2150 returns to STEP2160 to again detect motion, and thus providing a constant monitoringfor a loss of control mitigation method. In some embodiments, rotationalmotion is monitored prior to linear motion of the grinder 100.

FIGS. 22A, 22B, 22C, 22D, 22E, and 22F illustrate embodiments of agrinder including a connected second handle 105. In some examples, thegrinder includes some or all of the previously described features of thegrinder 100. The second handle 105 includes several differentembodiments regarding the movement and placement of the second handle105, making the second handle 105 adjustable to suit the user's needs.

As illustrated in FIG. 22A, an embodiment 2200 of the grinder 100includes the second handle 105. The second handle 105 includes, forexample a threaded screw for fastening the second handle to the grinder2200. The grinder 2200 includes corresponding threaded holes 2205 forreceiving the threaded screw of the second handle 105 on either side ofthe grinder 2200. FIG. 22A illustrates the second handle 105 in astandard position on a left-hand side of the grinder 2200 with thesecond handle 105 configured at a 90-degree angle to the grinder 2200.The second handle 105 can alternatively or additionally be positioned onthe right-hand side of the grinder 2200.

In some embodiments, if the 90-degree angle for the user is notconducive to the operation that the user is performing, an embodiment2210 of the grinder 100 can include the second handle 105 having apivoting mechanism 2215 for pivoting the second handle 105 from aposition perpendicular to the grinder 2210 to a position parallel to thegrinder 2210 (not shown), as illustrated in FIG. 22B. The pivotingmechanism 2215 allows for the second handle 105 to pivot towards thegrinder 2210. In some embodiments, the second handle 105 can attach tothe grinder 2210 using rails as described above with respect to FIGS.19A-19D. The second handle 105 can alternatively or additionally bepositioned on the right-hand side of the grinder 2210. In someembodiments, the pivoting mechanism includes a button to release thesecond handle 105 for movement of the second handle 105.

FIG. 22C illustrates an embodiment 2220 of the grinder 100 that includesa two-position pivoting handle. When the second handle 105 has pivotedaway the grinder 2220 to a primary position, the second handle 105 is anapproximately 90 degree angle (i.e., perpendicular) with respect to thegrinder 2220. In some embodiments, when the second handle is pivotedtoward a secondary position, the second handle 105 is in anapproximately 45 degree angle with respect to the grinder 100. In otherembodiments, the secondary position can be at another angle (e.g.,40-degrees, 60-degrees, etc.) with respect to the grinder 2220. Apivoting mechanism 2225 is connected between the handle 105 and thegrinder 2220 such that the second handle includes two (or possible more)discrete locked mechanical positions for securing the orientation of thesecond handle 105. The pivoting mechanism 2225 can then include athreaded screw or hole for securing the second handle 105 to acomplementary interface 2230 on the left and/or right side of thegrinder 2220.

In another embodiment 2240 of the grinder 100, the second handle 105 canbe secured to the grinder 2240 by a strap 2245, as illustrated in FIG.22D. A tightening mechanism 2250 can be rotated to slacken or tightenthe strap 2245 around the housing of the grinder 2240. Because the strap2245 secures the second handle 105 to the grinder 2240 by friction andnot a dedicated mechanical interface of the grinder 2240, the secondhandle can be rotated to any desirable orientation of the second handle105 perpendicular to the grinder 2240.

FIG. 22E illustrates in another embodiment 2260 of the grinder 100 thatincludes a pivoting mechanism 2265, similar to the pivoting mechanismsdescribed previously. The pivoting mechanism 2265 enables the secondhandle 105 to be pivoted closer to the grinder 2260 in a secondaryposition other than perpendicularly to the grinder 100. In someembodiments, the secondary position is in a 45 degree angle from thegrinder 2260. In other embodiments, the secondary position can be atanother angle (e.g., zero degrees, 20 degrees, 40 degrees, 60 degrees,etc.) with respect to the grinder 100. The pivoting mechanism is alsoattached to a pivot arm 2270 that permits the second handle 105 to berotated from the right side of the grinder 2260 to the left side of thegrinder 2260 about a pivot axis 2275. The grinder 2260 includes achannel 2280 for receiving the pivot arm 2270 on either side of thegrinder 2260. Once the second handle 105 is rotated to either side ofthe grinder, the pivot arm 2270 can be secured in place (e.g., by abutton and a retention mechanism, a lever, etc.) to secure the pivot arm2270 in place.

FIG. 22F illustrates the embodiment 2260 of the grinder 100 with thesecond handle 105 pivoted to be directly adjacent to the grinder at a0-degree angle in a fold-away position. By pivoting the second handle105 to be adjacent to the grinder 100, it allows for a more compact andefficient method of storage. In some embodiments, the fold-away positionprevents an opportunity for damage to occur to the second handle 105when the second handle 105 is secured against the main tool housing 120.The second handle 105 could be similarly stowed on the left side of thegrinder 2260.

FIGS. 23A, 23B, and 23C illustrate the grinder 100 including a guardpresence lockout system. The grinder that includes the guard presencesensor 215 for detecting the presence of the guard 130 on the grinder100. In some embodiments, the guard presence sensor 215 is anelectromechanical sensor (e.g., a pressure sensor) that is actuated whenthe guard 130 is coupled to the grinder 100 (e.g., a switch is closedwhen the guard 130 is attached to the grinder 100). In otherembodiments, the guard presence sensor 215 is an optical sensor that,for example, detects light reflected off of the guard 130 to detectpresence. In other embodiments, an inductive sensor, such as inductivesensor 400 illustrated in FIGS. 23B and 23C is used to detect the guard130. For example, the grinder 100 may only function if the inductivesensor 400 is at a certain distance from the guard 130, depending on thematerial of the guard 130. For example, the inductive sensor 400 must bewithin a minimum to maximum distance range to allow the grinder 100 tooperate. In some embodiments, the inductive sensor 400 detects theinductive response of the metal blade 150 placed in proximity to theinductive sensor. In other embodiments, the guard presence sensor 215detects the inductive response of the guard 130 based on material type(e.g., zinc, steel, zinc-plated steel, copper, aluminum, bronze, plasticwith metal film, glass with metal film, etc.), material thickness, ormaterial geometry. In some embodiments if the guard presence sensor 215detects that the inductive response of the guard 130 is outside adesired range, the controller 300 will halt the operation of the grinder100.

In some embodiments, the smaller the distance from the guard presencesensor 215 and the guard 130 itself, the greater the detected inductancechange will be. The reduced range between the guard presence sensor 215and the guard 130 provides a more accurate reading of an inductancevalue, allowing for a more accurate reading.

In some embodiments, the grinder 100 detects the type of componentconnected to the grinder 100. In this embodiment, the component is theguard 130. The detection of the particular type of component connectedto the grinder 100 is achieved using a sensor (e.g., an induction coil,a Hall effect sensor, an optical sensor, wireless communication, etc.)for detecting the type of component. For example, an induction coildetects if the guard 130 is coupled to the grinder 100 or if it isdisconnected from the grinder 100. In one embodiment, the induction coiland a reference coil are inputs to a differential switch, which returnsa binary “yes/no” or “I/O” output. The coil and reference coil can betuned such that metal guards are detected at varying distances from thesensor input.

As illustrated in FIG. 23B, the inductive sensor 2300 includes aninductor capacitor (“LC”) circuit formed by an inductor L and acapacitor C. The LC circuit is connected to an inductance-to-digitalconverter (“LDC”) 2305, which is used to measure proximity to metal bydetecting subtle changes in an alternating current (“AC”) magnetic fieldresulting from the interaction with a metal target 2315 (e.g., the metalguard). The LDC 2305 generates an AC magnetic field by supplying an ACcurrent into the LC circuit.

If a conductive target is brought into the vicinity of the AC magneticfield, small circulating currents (i.e., eddy currents 2310), will beinduced by the magnetic field onto the surface of the conductor (shownin FIG. 23C). The eddy currents 2310 produce their own magnetic fieldsthat oppose the magnetic field generated by the LC circuit. A resultinginductance shift is measured by the LDC 2305 and is used to provideinformation about the position of a metal target 2315 over a sensor coil(e.g., a distance to the metal target 2315, whether the metal target2315 is present or not, a characteristic of the metal target 2315,etc.). In some embodiments, the inductor L is a spiral or coil inductor,as illustrated in FIG. 23C. In some embodiments, the LC circuit islocated on a printed circuit board (“PCB”) that is positioned withinhousing of the grinder 100, as illustrated in FIG. 23A.

FIG. 23D illustrates a method 2350 to detect the presence of the guard130 and to ensure that the guard 130 is properly attached to the grinder100. When a user indicates an intention to use the grinder 100, acurrent is sent through the coil (i.e., LC circuit in FIG. 24B) (STEP2355) to attempt to detect the presence of metal in proximity to thegrinder 100. The current through the coil generates a magnetic field(STEP 2360). As described above, if a metal object is in proximity tothe inductive sensor 2300, eddy currents 2310 will be induced in themetal object. These eddy currents 2310 generate their own magnetic fieldthat opposes the magnetic field generated by the LC circuit. Themagnetic field from the eddy currents 2310 causes a change in theinductance of the LC circuit. The LDC 2305 monitors for this change ininductance (STEP 2365). If no change in inductance is detected at STEP2370, the grinder 100 will continue to monitor for a change ininductance. If a change in inductance is detected at STEP 2370, the LDC2305 generates an output signal indicative of the change in inductance(STEP 2375). In some embodiments, the LDC 2305 continuously outputs anoutput signal related to the inductance of the LC circuit. A valueassociated with that continuous output signal then change when theinductance of the LC circuit changes. The output signal is then sent orprovided to the controller 300 (STEP 2380). Based on the output signalfrom the LDC 2305, the controller 300 then determines whether the guard130 is present (STEP 2385). If the guard 130 is not present (e.g., nochange in inductance or not a significant enough change in inductance),the controller 300 prevents the motor 305 and grinder 100 from operating(STEP 2390). If the guard 130 is determined to be present, thecontroller 300 allows operation of motor 305 and grinder 100 (STEP2395).

FIG. 24 illustrates a method 2400 for the grinder 100 which includes anaccessory 150 (e.g., a grinder wheel) that can be used to grind (e.g.,cut) through a workpiece (STEP 2405). The grinder 100 is configured todetect when the grinder 100 has completed a cut through a workpiece. Thegrinder 100 includes a sensor (e.g., a current sensor) and is configuredto monitor a parameter (e.g., motor current) of the grinder 100 (STEP2410). In some embodiments, the parameter includes the motor current ofthe grinder 100. For example, a high current can be indicative of thegrinder being used to cut a workpiece. When the grinder cuts through theworkpiece, the amount of current drawn by the motor 305 decreases. Thisdecrease in current can be used to detect when cut through has occurred.In some embodiments, an additional sensor (e.g., a gyroscope) monitors amotion of the grinder 100 (STEP 2415). The grinder 100 detects a changein the parameter (e.g., motor current), such as a reduction in motorcurrent or loading of the grinder 100 (STEP 2420). The controller 300 ofthe grinder 100 then compares the change in the parameter to apredetermined threshold (STEP 2425). If the detected parameter isgreater than the predetermined threshold, the grinder continues tomonitor the parameter. If the detected parameter falls to or below thepredetermined threshold for the parameter, the grinder 100 determineswhether the motion of the grinder 100 is greater than a motion threshold(STEP 2430). For example, the motion of the grinder below the motionthreshold (e.g., a velocity, and acceleration, etc.) indicates a usermay be slowly pulling the grinder 100 away from a workpiece. In such aninstance, it may be undesirable to stop the motor 305. If the motion ofthe grinder 100 is greater than the motion threshold, the motor 305 isstopped (e.g. braked) (STEP 2435).

FIG. 25 illustrates an embodiment 2500 of the grinder 100 which includesa fixed guard 2515. The fixed guard 2515 is coupled to, for example, themain tool housing 120 of the grinder 100, and is unable to be removedfrom the main tool housing 120 of the grinder 100 by a user. The fixedguard 2515 is used to protect a user or another object in thesurrounding environment from the different accessory types that may beattached to the tool holder (e.g., a blade). In some embodiments, thefixed guard 2515 prevents a user from contacting the accessory. In someembodiments, the fixed guard 2515 provides protection against, forexample, sparks.

In some embodiments, the fixed guard 2515 is permanently affixed to agearcase 2505 including gearcase cover 2510 via a guard locking flange2520. The gearcase cover 2510 is an outer portion of the main toolhousing 120 which protects the gearcase 2505. Below both the gearcasecover 2510 and the gearcase 2505 are the fixed guard 2515 and the guardlocking flange 2520.

FIG. 26A illustrates an embodiment 2600 of the grinder 100 to attach thefixed guard 2515 to the gearcase cover 2510 via the guard locking flange2520. In some embodiments, a left handle thread and various torquedriving features are used to attach the fixed guard 2615 to the gearcasecover 2510. In other embodiments, the guard locking flange 2520 attachesthe fixed guard 2515 to the gearcase cover 2510 via a press fit into thegearcase cover 2510. FIG. 26B illustrates an additional retentionfeature for securing the fixed guard 2515 to the gearcase cover 2510. Insome embodiments, a blind roll pin 2610 is inserted through the gearcasecover 2510 as well as the guard locking flange 2520 to further securethe gearcase cover 2510 and the guard locking flange 2520 together. Insome embodiments, the blind roll pin 2610 is perpendicular to the outputshaft 125 of the grinder 100.

FIG. 27 illustrates a spindle locknut design 2700. In some embodiments,the spindle locknut design 2700 includes a spacer 2745. The spacer 2745includes a reduced thickness relative to conventional designs of aspindle locknut assembly. This reduced thickness allows the spindlelocknut design 2700 to position a ball bearing 2725 close to the blade150 when it is secured to a spindle shaft 2705. The ball bearing 2725then supports the spindle shaft 2705 to reduce vibrations imparted tothe spindle shaft 2705 by the blade 150 during a user's operation of thegrinder 100. In some embodiments, the ball bearing 2725 supporting thespindle shaft 2705 also protects the grinder 100's components, allowingthe grinder 100 to function for a longer period of time and reducing thechances that the grinder 100 will frequently require repairs.

The spindle locknut design 2700 further includes at least one discspring 2730 positioned between the ball bearing 2725 and a spindleflange 2740 to bias the spacer 2745 into engagement with the ballbearing 2725. In some embodiments, the spacer 2745 and the ball bearing2725 are coupled due to the disc spring 2730 being positioned betweenthe ball bearing 2725 and the spindle flange 2740. Furthermore, anotherspacer 2715 is positioned between a bevel gear 2710 and the ball bearing2725 to account for the ball bearing 2725 being positioned closer to anoutboard end of the spindle shaft 2705, the bevel gear 2710 beingdirectly above the spacer 2715. The spindle shaft 2705 is driven about alongitudinal axis by the bevel gear 2710. In some embodiments, thespindle locknut design 2700 further includes a locking flange 2735. Theblade 150 is positioned between the spindle flange 2740 and the lockingflange 2735, and is secured to the spindle shaft 2705 by tightening thelocking flange 2735 on the spindle shaft 2705 (e.g., using threads). Thelocking flange 2735 firmly secures spindle flange 2740 against thespacer 2745, which ensures that the ball bearing 2725 fixed against theother spacer 2715 allowing the spacer 2715 to properly be positionedagainst the bevel gear 2710. This embodiment reduces unnecessary andunwanted vibrations or movement that could cause damage to thecomponents of the grinder 100 and allows for smoother operation of thegrinder 100.

FIG. 28 illustrates an embodiment for the main tool housing 120. Themain tool housing 120 includes a lanyard integration assembly. Thelanyard integration assembly includes a lanyard interface 2800 affixedto or built into the surface of the main tool housing 120. In someembodiments, the lanyard interface 2800 is located by the rear of thegrinder 100, directly above a battery pack interface 2805. The lanyardinterface 2800 includes a component (e.g., a loop, a hook, etc.) that isoperable to attach a lanyard to the lanyard interface 2800. By attachinga lanyard to the grinder 100, the grinder 100 is less susceptible todropping or damage because the lanyard can secure the grinder 100 to auser (e.g., a belt).

FIG. 29 illustrates an embodiment 2900 of a battery pack interface thatincludes battery pack isolation features. During operation, the grinder100 may generate aggressive vibrational forces, so it is advantageous toisolate the vibrational forces within the grinder 100 so that thevibrational forces do not propagate to an attached battery pack. Excessvibrational forces exerted on the battery pack can limit the life cycleof the battery pack (e.g., loosen electrical connections, etc.). Thebattery pack interface 310 of the grinder 100 includes a plurality offront isolators 2905 (e.g., cylindrical isolators) and rear isolators2910 (e.g., cylindrical isolators). The front isolators 2905 arepositioned on a front end of the battery pack interface 310, and therear isolators 2910 are positioned on a rear end of the battery packinterface 310. By having both the front isolators 2905 and the rearisolators 2910, the battery pack experiences vibrational isolation oneither side of the battery pack. The battery pack interface 310 furtherincludes a rear ramp 2915. The rear ramp 2915 is used to secure thebattery pack to the battery pack interface 310 and press the batterypack against the isolators 2905, 2910.

FIG. 30 illustrates an embodiment of the grinder 100 including thesecond handle 105 and a wireless communication system 3000. The wirelesscommunication system 3000 includes a wireless receiver 3005 within themain tool housing 120. In some embodiments, the wireless receiver 3005is part of the controller 300. In some embodiments, the wirelessreceiver 3005 is separate from the controller 300. The second handle 105includes a wireless transmitter 3010. The wireless transmitter isconfigured to wirelessly communicate with the wireless receiver 3005.The wireless transmitter 3010 is electrically connected to themicroswitch sensor 608 which is configured to mechanically contact thefirst over-mold portion 403, as previously described. In someembodiments, when the microswitch sensor 608 detects the presence of ahand, the wireless transmitter 3010 transmits a signal to the wirelessreceiver 3005. In this embodiment, the wireless transmitter 3010 andwireless receiver 3005 perform the same functions as the previouslydescribed second handle 105 without the need for a wired connection. Insome embodiments, the second handle 105 includes a power source (e.g., abattery, a coin cell battery, etc.) for powering the transmitter 3010.

FIG. 31 illustrates a method 3100 for the grinder 100. In someembodiments, the method 3100 is referred to as cut-through breaking. Forexample, the method 3100 may include monitoring operation of the grinder100 such that when the controller 300 detects that the accessory 150 hascompleted a cutting operation, the controller 300 stops driving themotor 210. The method 3100 begins at step 3105, where the grinder 100 isbeing operated by a user and the motor 210 is being driven. The method3100 includes step 3110 where a parameter of the grinder 100 ismonitored. For instance, in some embodiments, a current sensor monitorsa current of the motor 305. The current sensor generates data associatedwith the current of the motor 305, and transmits the data to thecontroller 300. If, at step 3115, the motor parameter is less than athreshold value (e.g., motor current is less than a threshold value),the motor is stopped at step 3120 (e.g., indicating that cut-through hasoccurred). If the motor parameter is greater than or equal to thethreshold, the controller 300 continues to monitor the motor parameterat step 3110.

Thus, embodiments described herein provide, among other things, systemsand methods for a grinder with enhanced sensing and component detection.Various features and advantages are set forth in the following claims.

What is claimed is:
 1. A grinder comprising: a housing; a motor withinthe housing; a first handle including a first sensor configured todetect a presence of a user, the first handle attached to the housing; asecond handle attached to a pivot arm, the pivot arm attached to thehousing and configured to be pivoted around a circumference of thehousing, the second handle including a second sensor configured todetect the presence of the user; and a controller configured to controlthe motor based upon the detection of the presence of the user by thefirst sensor and the second sensor, wherein the controller prevents themotor from operating when second sensor does not detect the presence ofthe user by the second sensor.
 2. The grinder of claim 1, wherein thepivot arm further includes a locking mechanism, the locking mechanismconfigured to lock the pivot arm into one of a plurality of differentpositions around the circumference of the housing.
 3. The grinder ofclaim 2, wherein the plurality of different positions around thecircumference of the housing includes a left-handed position and aright-handed position.
 4. The grinder of claim 1, wherein the pivot armfurther includes a pivot mechanism configured to pivot the second handleinto one of a plurality of different positions with respect to the pivotarm.
 5. The grinder of claim 4, wherein the plurality of differentpositions with respect to the pivot arm include at least two discretepositions.
 6. The grinder of claim 1, wherein the second handle includesa microswitch sensor connected to a printed circuit board, themicroswitch sensor configured to detect the presence of a second hand ofthe user.
 7. The grinder of claim 6, wherein: the first sensor isconfigured to detect a first hand of the user; and the controller isconfigured to prevent the motor from operating if the first sensor doesnot detect the first hand of the user and the second sensor does notdetect the second hand of the user.
 8. The grinder of claim 1, whereinthe pivot arm further includes a wire routing portion through whichwires are routed from the second handle to the housing.
 9. The grinderof claim 8, wherein the wire routing portion includes a first channelwithin the pivot arm and a second channel that extends into the housing.10. The grinder of claim 1, the grinder further comprising: a wirelesstransmitter inside the second handle; and a wireless receiver inside thefirst handle, wherein the wireless transmitter is configured to transmita signal when the second sensor detects the presence of the user, andwherein the wireless receiver is configured to receive the signal andcommunicate to the controller that that the second sensor has detectedthe presence of the user.
 11. The grinder of claim 10, wherein: thesecond sensor is configured to detect a second hand of the user; and thecontroller is configured to prevent the motor from operating if thesecond sensor does not detect the second hand of the user.
 12. A methodof operating a grinder, the method comprising: prohibiting, by acontroller, the operation of the grinder; detecting, by a first sensor,a presence of a user's first hand; detecting, by a second sensor, thepresence of the user's second hand; and controlling, by the controller,a motor of the power tool based on the first sensor detecting thepresence of the user's first hand and the second sensor detecting thepresence of the user's second hand.
 13. The method of claim 12, furthercomprising: determining, by the controller, whether the second sensorhas detected the presence of the user's second hand within a period oftime after the first sensor detected the presence of the user's firsthand.
 14. The method of claim 13, further comprising: prohibiting, bythe controller, the operation of the grinder if the second sensor hasnot detected the presence of the user's second hand within the period oftime.
 15. A grinder comprising: a housing; a motor located within thehousing; a first handle including a first sensor configured to detectthe presence of a first hand of a user; a second handle attached to apivot arm, the pivot arm attached to the housing and configured to bepivoted around a circumference of the housing, the second handleincluding a second sensor configured to detect the presence of a secondhand of the user; a pivot mechanism attached to the pivot arm andconfigured to pivot the second handle into one of a plurality ofdifferent positions with respect to the pivot arm; and a controllerconfigured to control the motor based upon the detection of the presenceof the first hand of the user by the first sensor and the second hand ofthe user by the second sensor, wherein the controller prevents the motorfrom operating when the second sensor does not detect the presence ofthe second hand of the user.
 16. The grinder of claim 15, wherein thepivot arm further includes a locking mechanism, the locking mechanismconfigured to lock the pivot arm into one of a plurality of differentpositions around the circumference of the housing.
 17. The grinder ofclaim 16, wherein the plurality of different positions around thecircumference of the housing includes a left-handed position and aright-handed position.
 18. The grinder of claim 15, wherein theplurality of different positions with respect to the pivot arm includeat least two discrete positions.
 19. The grinder of claim 15, whereinthe pivot arm further includes a wire routing portion through whichwires are routed from the second handle to the housing.
 20. The grinderof claim 19, wherein the wire routing portion includes a first channelwithin the pivot arm and a second channel that extends into the housing.